Raspberry Diseases

The raspberry is the edible fruit of a multitude of plant species in the genus ''Rubus'' of the rose family, most of which are in the subgenus '' Idaeobatus''. The name also applies to these plants themselves. Raspberries are perennial with woody stems. World production of raspberries in 2020 was 895,771 tonnes, led by Russia with 20% of the total.

Description

A raspberry is an aggregate fruit, developing from the numerous distinct carpels of a single flower. What distinguishes the raspberry from its blackberry relatives is whether or not the torus ( receptacle or stem) "picks with" (i.e., stays with) the fruit. When picking a blackberry fruit, the torus stays with the fruit. With a raspberry, the torus remains on the plant, leaving a hollow core in the raspberry fruit.

Raspberries are grown for the fresh fruit market and for commercial processing into individually quick frozen (IQF) fruit, purée, juice, or as dried fruit used in a variety of grocery products such as raspberry pie. Raspberries need ample sun and water for optimal development. Raspberries thrive in well-drained soil with a pH between 6 and 7 with ample organic matter to assist in retaining water. While moisture is essential, wet and heavy soils or excess irrigation can bring on '' Phytophthora'' root rot, which is one of the most serious pest problems facing the red raspberry. As a cultivated plant in moist, temperate regions, it is easy to grow and has a tendency to spread unless pruned. Escaped raspberries frequently appear as garden weeds, spread by seeds found in bird droppings.

An individual raspberry weighs , and is made up of around 100 drupelets, each of which consists of a juicy pulp and a single central seed. A raspberry bush can yield several hundred berries a year. Unlike blackberries and dewberries, a raspberry has a hollow core once it is removed from the receptacle.

File:Raspberries from Srem, Serbia (sremske maline, Dobrinci).jpg, Raspberries from Serbia
File:Raspberries at Ljubljana Central Market.JPG, Raspberries for sale in plastic punnets at Ljubljana Central Market
File:Raspberry - halved (Rubus idaeus).jpg, Halved raspberry with absent torus
File:Halved blackberry (Rubus fruticosus).jpg, Halved blackberry with present torus

Etymology

Raspberry derives its name from ''raspise'', "a sweet rose-colored wine" (mid-15th century), from the Anglo-Latin ''vinum raspeys'', or from ''raspoie'', meaning "thicket", of Germanic origin. The name may have been influenced by its appearance as having a rough surface, related to Old English ''rasp'' or "rough berry".

Species

Examples of raspberry species in ''Rubus'' subgenus '' Idaeobatus'' include:
* '' Rubus crataegifolius'' (Asian raspberry)
* '' Rubus gunnianus'' (Tasmanian alpine raspberry)
* '' Rubus idaeus'' (red raspberry or European red raspberry)
* '' Rubus leucodermis'' (whitebark raspberry or western raspberry, blue raspberry, black raspberry)
* ''Rubus occidentalis'' (black raspberry)
* ''Rubus parvifolius'' (Australian native raspberry)
* ''Rubus phoenicolasius'' (wine raspberry or wineberry)
* ''Rubus rosifolius'' (Mauritius raspberry)
* '' Rubus strigosus'' (American red raspberry) (syn. ''R. idaeus'' var. ''strigosus'')
* '' Rubus ellipticus'' (yellow Himalayan raspberry)

Several species of ''Rubus'', also called raspberries, are classified in other subgenera, including:
* ''Rubus deliciosus'' (boulder raspberry, subgenus ''Anoplobatus'')
* ''Rubus odoratus'' (flowering raspberry, subgenus ''Anoplobatus'')
* ''Rubus nivalis'' (snow raspberry, subgenus ''Chamaebatus'')
* ''Rubus arcticus'' (Arctic raspberry, subgenus ''Cyclactis'')
* '' Rubus sieboldii'' (Molucca raspberry, subgenus ''Malachobatus'')

Cultivation

Various kinds of raspberries can be cultivated from hardiness zones 3 to 9. Raspberries are traditionally planted in the winter as dormant canes, although planting of tender, plug plants produced by tissue culture has become much more common. A specialized production system called "long cane production" involves growing canes for a year in a northern climate such as Scotland or Oregon or Washington, where the chilling requirement for proper bud break is attained, or attained earlier than the ultimate place of planting. These canes are then dug, roots and all, to be replanted in warmer climates such as Spain, where they quickly flower and produce a very early season crop. Plants are typically planted 2–6 per m in fertile, well drained soil; raspberries are usually planted in raised beds/ridges, if there is any question about root rot problems.

All cultivars of raspberries have perennial roots, but many do not have perennial shoots. In fact, most raspberries have shoots that are biennial (meaning shoots grow in the first growing season and fruits grow on those shoots during the second growing season). The flowers can be a major nectar source for honeybees and other pollinators.

Raspberries are vigorous and can be locally invasive. They propagate using basal shoots (also known as suckers), extended underground shoots that develop roots and individual plants. They can sucker new canes some distance from the main plant. For this reason, raspberries spread well, and can take over gardens if left unchecked. Raspberries are often propagated using cuttings, and will root readily in moist soil conditions.

The fruit is harvested when it comes off the receptacle easily and has turned a deep color (red, black, purple, or golden yellow, depending on the species and cultivar). This is when the fruits are ripest and sweetest.

High tunnel bramble production offers the opportunity to bridge gaps in availability during late fall and late spring. Furthermore, high tunnels allow less hardy floricane-fruiting raspberries to overwinter in climates where they would not otherwise survive. In the tunnel plants are established at close spacing usually prior to tunnel construction.

Cultivars

Major cultivars

Raspberries are an important commercial fruit crop, widely grown in all temperate regions of the world. Many of the most important modern commercial red raspberry cultivars derive from hybrids between '' R. idaeus'' and '' R. strigosus''.Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan . Some botanists consider the Eurasian and American red raspberries to belong to a single, circumboreal species, ''Rubus idaeus'', with the European plants then classified as either ''R. idaeus'' subsp. ''idaeus'' or ''R. idaeus'' var. ''idaeus'', and the native North American red raspberries classified as either ''R. idaeus'' subsp. ''strigosus'', or ''R. idaeus'' var. ''strigosus''. Recent breeding has resulted in cultivars that are thornless and more strongly upright, not needing staking.

The black raspberry, ''Rubus occidentalis'', is also cultivated, providing both fresh and frozen fruit, as well as jams, preserves, and other products, all with that species' distinctive flavor.

Purple raspberries have been produced by horticultural hybridization of red and black raspberries, and have also been found in the wild in a few places (for example, in Vermont) where the American red and the black raspberries both grow naturally. Commercial production of purple-fruited raspberries is rare.

''Blue raspberry'' is a local name used in Prince Edward County, Ontario, Canada for the cultivar 'Columbian', a hybrid (purple raspberry) of ''R. strigosus'' and ''R. occidentalis''. ''Blue raspberry'' can also refer to the whitebark raspberry, '' R. leucodermis''.

Fruits from such plants are called golden raspberries or yellow raspberries; despite their similar appearance, they retain the distinctive flavor of their respective species (red or black). Most pale-fruited raspberries commercially sold in the eastern United States are derivatives of red raspberries. Yellow-fruited variants of the black raspberry are sometimes grown in home gardens.

Red raspberries have also been crossed with various species in other subgenera of the genus ''Rubus'', resulting in a number of hybrids, the first of which was the loganberry. Later notable hybrids include the olallieberry, boysenberry, marionberry, and tayberry; all are multi-generational hybrids. Hybridization between the familiar cultivated red raspberries and a few Asiatic species of ''Rubus'' has also been achieved.

Selected cultivars

Numerous raspberry cultivars have been selected.

Two types of raspberry are available for commercial and domestic cultivation; the summer-bearing type produces an abundance of fruit on second-year canes (floricanes) within a relatively short period in midsummer, and double or "everbearing" plants, which also bear some fruit on first-year canes (primocanes) in the late summer and fall, as well as the summer crop on second-year canes. Those marked (AGM) have gained the Royal Horticultural Society's Award of Garden Merit.

= Red, Early Summer fruiting

=

* Boyne
* Fertödi Venus
* Rubin Bulgarski
* Cascade Dawn
* Glen Clova
* Glen Moy (AGM)
* Killarney
* Malahat
* Malling Exploit
* Malling Jewel (AGM)
* Titan
* Willamette
* Prelude

= Red, Mid-summer Fruiting

=

* Cuthbert
* Glen Ample (AGM)
* Lloyd George
* Meeker
* Newburgh
* Ripley
* Skeena
* Cowichan
* Chemainus
* Saanich

= Red, Late Summer Fruiting

=

* Cascade Delight
* Coho
* Fertödi Rubina
* Glen Magna (AGM)
* Leo (AGM)
* Malling Admiral (AGM)
* Octavia
* Schoenemann
* Tulameen (AGM)

= Red primocane, Autumn fruiting

=

* Amity
* Augusta
* Autumn Bliss (AGM)
* Joan J. (Thornless)
* Caroline
* Fertödi Kétszertermö
* Heritage
* Imara
* Joan J
* Josephine
* Kwanza
* Kweli
* Mapema
* Polka (AGM)
* Rafiki
* Ripley
* Summit
* Zeva Herbsternte

= Yellow primocane, Autumn fruiting

=

* Anne
* Fallgold
* Fertödi Aranyfürt
* Goldenwest
* Golden Queen
* Honey Queen
* Jambo
* Kiwi Gold

= Purple

=

* Brandywine
* Glencoe
* Royalty

= Black

=

* Black Hawk
* Bristol
* Cumberland
* Jewel
* Munger
* Ohio Everbearer
* Scepter

= Dwarf cultivars

=
* = 'Nr7'

Diseases and pests

Raspberries are sometimes eaten by the larvae of some Lepidoptera species (butterflies and moths). More serious are the raspberry beetle (in Europe) and the raspberry fruitworm (in North America), whose larvae can damage raspberries.

''Botrytis cinerea'', or gray mold, is a common fungal infection of raspberries and other soft fruit under wet conditions. It is seen as a gray mold growing on the raspberries, and particularly affects fruit which are bruised, as it provides an easy entrance point for the spores.

Raspberry plants should not be planted where potatoes, tomatoes, peppers, eggplants, or bulbs have previously been grown, without prior fumigation of the soil. These crops are hosts for the disease ''Verticillium'' wilt, a fungus that can stay in the soil for many years and can infest the raspberry crop.

Production

In 2020, world production of raspberries was 895,771 tonnes, led by Russia with 20% of the world total (table). Other major producers were Mexico, Poland, Serbia, and the United States.

Nutrition

Raw raspberries are 86% water, 12% carbohydrates, and have about 1% each of protein and fat (table). In a 100 gram amount, raspberries supply 53 kilocalories and 6.5 grams of dietary fiber. Raspberries are a rich source (20% or more of the Daily Value, DV) of vitamin C (32% DV), manganese (32% DV) and dietary fiber (26% DV), but otherwise have low content of micronutrients (table). Raspberries are a low-glycemic index food, with total sugar content of only 4% and no starch.

The aggregate fruit structure contributes to raspberry's nutritional value, as it increases the proportion of dietary fiber, which is among the highest known in whole foods, up to 6% fiber per total weight.

Phytochemicals

Raspberries contain phytochemicals, such as anthocyanin pigments, ellagic acid, ellagitannins, quercetin, gallic acid, cyanidins, pelargonidins, catechins, kaempferol and salicylic acid. Yellow raspberries and others with pale-colored fruits are lower in anthocyanin content. Both yellow and red raspberries contain carotenoids, mostly lutein esters, but these are masked by anthocyanins in red raspberries.

Raspberry compounds are under preliminary research for their potential to affect human health.

Leaves

Raspberry leaves can be used fresh or dried in herbal teas, providing an astringent flavor. In herbal and traditional medicine, raspberry leaves are used for some remedies, although there is no scientifically valid evidence to support their medicinal use.

Comparison

See also

* Blue raspberry flavor
* Chambord (liqueur)
* Framboise
* List of culinary fruits
* Raspberry ketone
* Raspberry juice
* Red raspberry leaf (herb)
* Thimbleberry

References

Further reading

* Funt, R.C. / Hall, H.K. (2012). ''Raspberries'' (Crop Production Science in Horticulture). CABI.

External links

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*

Raspberries & More
(University of Illinois Extension)

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Berries
Plant common names
Rubus

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